439 research outputs found

    Extending local features with contextual information in graph kernels

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    Graph kernels are usually defined in terms of simpler kernels over local substructures of the original graphs. Different kernels consider different types of substructures. However, in some cases they have similar predictive performances, probably because the substructures can be interpreted as approximations of the subgraphs they induce. In this paper, we propose to associate to each feature a piece of information about the context in which the feature appears in the graph. A substructure appearing in two different graphs will match only if it appears with the same context in both graphs. We propose a kernel based on this idea that considers trees as substructures, and where the contexts are features too. The kernel is inspired from the framework in [6], even if it is not part of it. We give an efficient algorithm for computing the kernel and show promising results on real-world graph classification datasets.Comment: To appear in ICONIP 201

    EX VIVO ANTICOAGULANT ACTIVITY OF 1, 3, 4-OXADIAZOLE DERIVATIVES

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    Objective: The present medication for the management of arterial thromboembolism (ATE) disorders by anticoagulant therapy highlights its lacunae due to recurrent ATE episodes and indicates the need for better anticoagulant agents with clinical advantage.Methods: The anticoagulant study was performed for increase in prothrombin time (PT) and activated partial thromboplastin time (aPTT) at a test dose of 25 mg kg-1.Results: The results of ex vivo anticoagulant evaluation revealed that the tested compounds 3a-3q did not exhibit a significant increase in PT with respect to acenocoumarol (1 mg kg-1) employed as the reference drug for increase in PT. While the compounds, 3a-3q exhibited minimal increase in aPTT in comparison to unfractionated heparin (500 IU kg-1) employed as the reference drug for increase in aPTT. Among all the tested compounds, only compound 3q exhibited moderate anticoagulant activity with an increase in PT (33 ± 0.4 s) to that of the reference drug acenocoumarol (48 ± 0.5 s).Conclusion: The anticoagulant efficacy investigation highlights that the synthesized compound 3q could be considered for further clinical studies to ascertain its possible hit as anticoagulant agents.Â

    Graph Kernels

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    We present a unified framework to study graph kernels, special cases of which include the random walk (Gärtner et al., 2003; Borgwardt et al., 2005) and marginalized (Kashima et al., 2003, 2004; Mahé et al., 2004) graph kernels. Through reduction to a Sylvester equation we improve the time complexity of kernel computation between unlabeled graphs with n vertices from O(n^6) to O(n^3). We find a spectral decomposition approach even more efficient when computing entire kernel matrices. For labeled graphs we develop conjugate gradient and fixed-point methods that take O(dn^3) time per iteration, where d is the size of the label set. By extending the necessary linear algebra to Reproducing Kernel Hilbert Spaces (RKHS) we obtain the same result for d-dimensional edge kernels, and O(n^4) in the infinite-dimensional case; on sparse graphs these algorithms only take O(n^2) time per iteration in all cases. Experiments on graphs from bioinformatics and other application domains show that these techniques can speed up computation of the kernel by an order of magnitude or more. We also show that certain rational kernels (Cortes et al., 2002, 2003, 2004) when specialized to graphs reduce to our random walk graph kernel. Finally, we relate our framework to R-convolution kernels (Haussler, 1999) and provide a kernel that is close to the optimal assignment kernel of Fröhlich et al. (2006) yet provably positive semi-definite

    OVERCOMING SITUATIONAL CONSTRAINTS IN COMMUNICATIVE LANGUAGE TEACHING

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    ABSTRACT It is well known that norms that enjoy prestige in English teaching still emanate from and find inspiration in the Anglo American models that assume universal applicability of approaches, methods and materials. The flow of information and aid being unidirectional, countries that use English in the outer and expanding circle (Kachru, 1985) often treat imports as the best and most convenient means of taking English to learners, no matter what the actual conditions and circumstances under which learning is predicated. One such import is Communicative Language Teaching (CLT), an approach that originally sought to teach English in natural settings and where learners feel at home mastering the second/foreign language with minimum inconvenience. Studies have shown that CLT may not be all that it was made out to be and that some modifications are called for to render teaching and learning effective. This study looks at the possibility of using CLT after introducing certain alterations that meet the needs of learners in a heterogeneous, multilingual setting

    DESIGN, SYNTHESIS, IN VITRO ANTIOXIDANT AND IN VIVO ANTI-INFLAMMATORY ACTIVITIES OF NOVEL OXADIAZOLE DERIVATIVES

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    Objective: In the present study, a series of novel 1,3,4-oxadiazole derivatives (3a-3q) were designed, synthesized and evaluated for antioxidant and anti-inflammatory activities.Methods: The title compounds were designed and docked onto the COX-2 enzyme (3LN1) protein using SYBYLX 2.1. 2-substituted-5-(5-nitrobenzofuran-2-yl)-1,3,4-oxadiazole derivatives (3a-3p) were synthesized from acid catalyzed dehydrative cyclization of 5-nitrobenzofuran-2-carbohydrazide (2) with various heteroaryl/aryl/aliphatic carboxylic acid derivatives. And 5-(5-nitrobenzofuran-2-yl)-1,3,4-oxadiazole-2-thiol (3q) was synthesized on reacting the hydrazide derivative 2 with carbon disulfide. The synthesized compounds were evaluated for in vitro antioxidant property by DPPH radical scavenging assay method and in vivo anti-inflammatory activity by carrageenan induced paw edema method.Results: The synthesized 1,3,4-oxadiazole derivatives (3a-3q) were characterized on the basis of LCMS, 1HNMR [13]CNMR, IR and elemental analysis. The title compounds 3a-3q exhibited significant antioxidant efficacy ranging from 34 to 86%and the results of anti-inflammatory evaluation revealed that compounds 3c, 3e and 3d exhibited substantial anti-inflammatory activity of 72, 68 and 65%, respectively, at a dose of 50 mg kg-1.Conclusion: A significant correlation was observed between the in silico study and the anti-inflammatory results. The anti-inflammatory results highlight the synthesized compounds 3c, 3e and 3d could be considered as possible hit as therapeutic agents.Â

    Genetic structure and affinities among tribal populations of southern India: a study of 24 autosomal DNA markers

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    We describe the genetic structure and affinities of five Dravidian-speaking tribal populations inhabiting the Nilgiri hills of Tamil Nadu, in south India, using 24 autosomal DNA markers. Our goals were: (i) to examine what evolutionary forces have most significantly impacted south Indian tribal genetic variation, and (ii) to test whether the phenotypic similarities of some south Indian tribal groups to Africans represent a signature of close relationship to Africans or are due to convergence. All loci were polymorphic and average heterozygosities were substantial (range: 0.347-0.423). Genetic differentiation was high (Gst= 6.7%) and genetic distances were not significantly correlated with geographic distances. Genetic drift therefore probably played a significant role in shaping the patterns of genetic variation observed in southern Indian tribal populations. Otherwise, analyses of population relationships showed that Indian populations are closely related to one another, regardless of phenotypic characteristics, and do not show particular affinities to Africans. We conclude that the phenotypic similarities of some Indian groups to Africans do not reflect a close relationship between these groups, but are better explained by convergence

    Impact of proctoring on success rates for percutaneous revascularisation of coronary chronic total occlusions.

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    OBJECTIVE: To assess the impact of proctoring for chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in six UK centres. METHODS: We retrospectively analysed 587 CTO procedures from six UK centres and compared success rates of operators who had received proctorship with success rates of the same operators before proctorship (pre-proctored) and operators in the same institutions who had not been proctored (non-proctored). There were 232 patients in the pre-proctored/non-proctored group and 355 patients in the post-proctored group. Complexity was assessed by calculating the Japanese CTO (JCTO) score for each case. RESULTS: CTO PCI success was greater in the post-proctored compared with the pre-proctored/non-proctored group (77.5% vs 62.1%, p<0.0001). In more complex cases where JCTO≥2, the difference in success was greater (70.7% vs 49.5%, p=0.0003). After proctoring, there was an increase in CTO PCI activity in centres from 2.5% to 3.5%, p<0.0001 (as a proportion of total PCI), and the proportion of very difficult cases with JCTO score ≥3 increased from 15.3% (35/229) to 29.7% (105/354), p<0.0001. CONCLUSIONS: Proctoring resulted in an increase in procedural success for CTO PCI, an increase in complex CTO PCI and an increase in total CTO PCI activity. Proctoring may be a valuable way to improve access to CTO PCI and the likelihood of procedural success

    (ELT) Group Discussion in an ESL Classroom: A Socio-cultural Perspective 245 ================================================================= Language in India www.languageinindia

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    Abstract The benefits of Group Discussion (GD) and its importance as a parameter for judging a potential candidate&apos;s performance in interviews have long been recognized, and GD has been accorded a place of honour in the &apos;English&apos; curriculum of engineering colleges. Recruiters have in recent times used GD as a yardstick for judging a prospective Yet the non-participation of some learners in a GD may be attributed to socio-cultural factors that need to be examined to understand the reasons for non-participation and find ways to invite better participation from the silent learners without making them feel ashamed or alienated in any way. Keywords: GD, second language classroom, CLT, socio-cultural factors Scene 1: Inside campus bus: I was witness to a strange incident while travelling to college by college bus. The bus I was travelling in stopped at a place to pick up passengers en route to college and on the particular day, there were several vacant seats since several three seaters were occupied by a lone passenger. Yet those who got in, all of them boys were standing at the footboard or huddled near the driver&apos;s area. When asked to occupy the vacant seats, they refused. Curiosity set me asking them the reason
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